ASKSAGE: Sage Q&A Forum - Latest question feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Wed, 03 Feb 2016 19:30:48 -0600Get vector from abelian grouphttps://ask.sagemath.org/question/32436/get-vector-from-abelian-group/ I want to represent the Cayley graph of an abelian group (let's say $A=Z_5^2$) is a way that the element $g=a^i b^j$ is in the position $[i,j]$. I need a method `.pos()`such that:
A= groups.presentation.FGAbelian([n,n]);
g=A[2]
---> g = a*b*a^-1
g.pos()
---> [0,1]
How could I do that?
MLainzWed, 03 Feb 2016 19:30:48 -0600https://ask.sagemath.org/question/32436/Direct product for finitely presented groupshttps://ask.sagemath.org/question/10367/direct-product-for-finitely-presented-groups/I am currently trying to implement a direct product function for finitely presented groups by wrapping GAP's DirectProduct method. I have placed a constructor <code>direct_product_groups</code>, which appears in the global namespace, in the top level groups.pyx file, which accepts a list of groups as input. The function then checks the representations of the groups listed, and calls the appropriate constructor
such as <code>direct_product_permgroups</code> or <code>direct_product_fpgroups</code>,
which I am currently implementing as a private constructor.
My goal for <code>direct_product_groups</code> is that it will eventually completely mimic GAP's DirectProduct in that it takes a list of groups in any representation, and outputs their direct product in an appropriate representation. But for now, it behaves simply by punting its input to other, more specific constructors.
I was wondering if this approach is prefered, if this functionality is already implemented somewhere, or if anyone has any suggestions/thoughts/critiques at all. I'm new to Sage and want to get a feel for the response to this enhancement before it is posted to trac.
-dshurbertdshurbertSat, 20 Jul 2013 11:12:07 -0500https://ask.sagemath.org/question/10367/How do I find a presentation for classical matrix groups like PGL(2,q)?https://ask.sagemath.org/question/9743/how-do-i-find-a-presentation-for-classical-matrix-groups-like-pgl2q/I know I can just take the group and do ".gens()", and that'll give me a list of generators, but is there a way to find the relations on them?
Also, is there a way to compute generators for kernels of group homomorphisms?oxeimonFri, 25 Jan 2013 17:23:53 -0600https://ask.sagemath.org/question/9743/